In this year, we completed two major sub-projects. First, we employed glutamate-sensitive sensors coupled with high-speed amperometry to evaluate rapid changes in glutamate following exposure to natural arousing stimuli, cocaine and nicotine. Second, we employed glucose-sensitive sensors coupled with high-speed amperometry to evaluate rapid fluctuations in brain glucose levels following exposure to natural stimuli and drugs of abuse (cocaine and nicotine). We also initiated third project, in which we want to examine how glucose enters the brain after iv injections of several drugs of abuse with different mechanisms of action (cocaine, methamphetamine and MDPV). This work will be expanded during the next years to include more complicated behavioral paradigms that involve the use of addictive drugs.